Equilibrium Hydrate Formation Conditions for the Mixtures of CO₂ + H₂ + Tetrabutyl Ammonium Bromide

Abstract

The equilibrium hydrate formation conditions for the gas mixture of CO2 and H2 with tetrabutyl ammonium bromide (TBAB) are measured. The data show that TBAB can reduce the gas hydrate formation pressure as an additive with the mole fraction of (0.14, 0.21, 0.29, 0.50, 1.00, and 2.67) %. The experiments were carried out in the temperature range of (274.05 to 288.55) K and the pressure range of (0.25 to 7.26) MPa. The equilibrium hydrate formation pressure of the CO2 + H2 + TBAB mixture is remarkably lower than that of the CO2 + H2 mixture at the same temperature and decreases with the increase in the concentration of TBAB. In addition, to avoid the formation of pure TBAB hydrate, in which there are no CO2 or H2, for the above gas mixture, the formation conditions of the pure TBAB hydrate with TBAB mole fraction from (0.14 to 2.67) % were also measured.